Merge pull request #77 from hlee/master

data structure
update vote
Merge pull request #78 from hlee/master

no answer question
Partly for #48
Merge pull request #79 from hlee/master

rspec for no answer question partly for #48
fixed the time of the questions
Merge pull request #80 from Jael/master

修改了时间的显示
Merge pull request #81 from hlee/master

show no answer questions list
Fixed #48
Merge pull request #82 from hlee/master

Fixed break spec of answer counter
add chosen
Merge pull request #84 from caok/chosen

add chosen
modify question show layout
add user info into question show page and remove side about us paragraph
change new question to I want to ask question
modify answers showing
add tags cloud to the side bar and change some english letter to chinese
Merge pull request #86 from hlee/master

one more counter cache for answer
Merge pull request #87 from hlee/master

Counter cache for answer
Merge pull request #89 from hlee/master

chain no answer question
Fixed #88
Merge pull request #92 from hlee/master

no_answer should not need sign in
Fixed #91
add the default user_image